The Proteomics Shared Resource (PSR) is a specialized technical facility with the primary goal of protein identification, characterization and quantitation, and is open to all Cancer Center members at CSHL. The Proteomics Shared Resource is located within the W.M. Keck Structural Biology Laboratory on the ground floor ofthe Beckman building. In the last 18 months CSHL has completed a major restructuring ofthe Resource. A senior faculty member with significant expertise in proteomics was recruited to redesign and oversee the Shared Resource. In addition, a PhD-level scientist with experience in proteomics and mass spectrometry was recruited to manage and run the facility. With the new staff in place, state-of-the-art equipment was purchased and the laboratory space was extensively renovated. The Resource features new, state-of-the-art equipment, including: one Thermo LTQ-Orbitrap mass spectrometer, one Thermo LTQ iontrap mass spectrometer, one Agilent 6520 quadrupole time-of-flight (QTOF) mass spectrometer and one Thermo Vantage triple quadrupole mass spectrometer, all fitted with nano electrospray (NanoESl) sources. A second Orbitrap Velos mass spectrometer with ETD source (funded through the High-End Instrumentation program) is due to be installed in late 2010. An additional Accela HPLC and autosampler is also available for analytical scale MRM work using the Vantage triple-Quad.